Rack server system and control method thereof

ABSTRACT

A rack server system and a control method thereof are provided. The rack server system establishes a communication link for communicating with a battery backup unit. The battery backup unit is connected to a power input port of the rack server system, and includes a number of battery modules connected with each other in parallel. The rack server system controls the battery backup unit to perform validity test on a first battery module during a first period and to perform validity test on a second battery module during a second period, wherein the first period and the second period are not overlapped with each other.

This application claims the benefit of Taiwan application Serial No.100126882, filed Jul. 28, 2011, the subject matter of which isincorporated herein by reference.

TECHNICAL FIELD

The disclosure relates in general to a rack server system and a controlmethod thereof, and more particularly to a rack server system whichcontrols a battery backup unit via a communication interface to performvalidity test and a control method thereof.

BACKGROUND

A battery backup unit may replace the uninterruptible power supply(UPS). Under the circumstances when abnormality (such as power off,power insufficient, power interference or surge) occurs to a main powersupplied to a rack server system, the battery backup unit supplies powerto the rack server system to maintain normal operation; and a powersupply apparatus such as a power generator is activated to providebackup power. In general, the battery backup unit is used formaintaining necessary operations for critical commercial or precisionapparatuses, such as rack server systems, switches, to prevent data losslest the business might suffer from tremendous loss or other unexpectedconsequences.

Validity of the battery backup unit has much to do with systemstability. If the battery backup unit fails due to aging or otherfactors, the battery backup unit may not maintain the normal operationof the rack server system when abnormality occurs to the main powersupplied to the rack server system, and data may be lost. To assure thevalidity of the battery backup unit, validity test such as dischargetest is performed on the battery backup unit periodically to obtainwhether the battery has sufficient power.

However, if abnormity, such as power off, occurs to the main powersupplied to the rack server system when the battery backup unit is indischarge test, power stored in the battery backup unit may be nearlyused up and the battery backup unit may be unable to maintain the normaloperation of the rack server system. Meanwhile, the rack server systemmay have stability problem which may lead to data loss. Therefore, howto reduce the risk of data loss of the rack server system has become aprominent task for the industries.

SUMMARY OF THE DISCLOSURE

The disclosure is directed to a rack server system and a control methodthereof which reduce the risk of data loss of the rack server systemwhen a battery backup unit is in validity test.

According to an example of the present disclosure, a control methodapplicable to a rack server system is provided. The rack server systemestablishes a communication link for communicating with a battery backupunit. The battery backup unit is connected to a power input port of therack server system, and includes a number of battery modules connectedwith each other in parallel. The rack server system controls the batterybackup unit to perform a validity test on a first battery module duringa first period and to perform a validity test on a second battery moduleduring a second period, wherein the first period and the second periodare not overlapped with each other.

According to another example of the present disclosure, a rack serversystem is provided. The rack server system includes a power input port,a communication interface and a control unit. The power input port isconnected to a battery backup unit. The battery backup unit includes anumber of battery modules connected with each other in parallel. Thecommunication interface establishes a communication link forcommunicating with the battery backup unit. The control unit isconnected to the communication interface. The control unit controls thebattery backup unit to perform a validity test on a first battery moduleduring a first period and to perform a validity test on the validity ofa second battery module during a second period, wherein the first periodand the second period are not overlapped with each other.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are not restrictive of the disclosed embodiments, as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a flowchart of a control method according to one embodimentof the disclosure;

FIG. 2 shows a block diagram of an example of a rack server system and abattery backup unit according to one embodiment of the disclosure;

FIG. 3A and FIG. 3B show timing diagrams of an example of communicationbetween the rack server system and the battery backup unit of FIG. 2;and

FIG. 4 shows a block diagram of another example of a rack server systemand a battery backup unit according to one embodiment of the disclosure.

DETAILED DESCRIPTION OF THE DISCLOSURE

A rack server system and a control method thereof are disclosed in anumber of embodiments below. In some embodiments, a battery backup unitincludes a number of battery modules connected in parallel. The batterymodules are controlled by a rack server system via a communicationinterface; and validity test such as discharge test is performed on thebattery modules in time-sharing. In other words, when a part of thebattery modules are under validity test, other part of the batterymodules are not under validity test and are ready to provide power tothe rack server system. Thus, the risk of data loss of the rack serversystem is reduced.

Referring to FIG. 1, a flowchart of a control method according to oneembodiment of the disclosure is shown. The control method is for use inthe rack server system. At step S110, the rack server system establishesa communication link for communicating with a battery backup unit. Thebattery backup unit is connected to a power input port of the rackserver system. The battery backup unit includes a number of batterymodules connected in parallel. At step S120, the rack server systemcontrols the battery backup unit to test validity of a first batterymodule of the battery backup unit during a first period. At step S130,the rack server system controls the battery backup unit to test validityof a second battery module of the battery backup unit during a secondperiod. The first period and the second period are not overlapped witheach other. The two non-overlapping periods refer that the two batterymodules of the battery backup unit are under validity test intime-sharing to reduce the risk of data loss of the rack server system.

Referring to FIG. 2, a block diagram of an example of the rack serversystem and the battery backup unit according to one embodiment of thedisclosure is shown. The rack server system 200 may be realized by suchas but not limited to a cloud computing rack server system. The rackserver system 200 such as includes a number of servers (not illustrated)inside a rack. The rack server system 200 at least includes a powerinput port 210, a communication interface 220, and a control unit 230.In FIG. 2, the rack server system 200 of the present example isillustrated as a basic model for convenience of elaborating theembodiments of the disclosure, and in fact, rack server system shouldinclude other circuits not illustrated here.

The power input port 210 is connected to a battery backup unit 300. Forexample, the power input port 210 may be realized by a DC power inputport for receiving DC power. The power input port 210 may include two ormore input ends for receiving DC power having different polarities ordifferent levels such as receiving power from an AC/DC power supply orreceiving power from the battery backup unit 300. When abnormalityoccurs to a main power supplied the rack server system 200, the powerinput port 210 feeds the power from the battery backup unit 300 to thesystem 200, such that the system 200 is powered for maintaining normaloperations.

The communication interface 220 establishes a communication link forcommunicating with the battery backup unit 300. In some embodiments, thecommunication interface 220 is a wireless communication interface suchas Bluetooth, wireless fidelity (Wi-Fi), or other wireless communicationstandards or wireless communication protocols. In some otherembodiments, the communication interface 220 is such as a wirecommunication interface, which may be connected to the battery backupunit 300 via a communication bus 240 of the rack server system 200. Thecommunication bus 240 is such as an RS232 bus, an I²C bus, a controllerarea network (CAN) bus, or other bus.

The control unit 230 is connected to the communication interface 220.Via the communication interface 220, the control unit 230 controls thebattery backup unit 300 to perform validity test on the battery backupunit 300. In the present embodiment of the disclosure, the batterybackup unit 300 includes a number of battery modules 310-1˜310-nconnected in parallel as indicated in FIG. 2. The control unit 230 plansor arranges execution times and execution sequence of validity tests onthe battery modules 310-1˜310-n for reducing risk of data loss of therack server system.

In some embodiments, the control unit 230 may control the battery backupunit 300 to test validity of the battery modules 310 one by one,sequentially or non-concurrently. For example, the control unit 230 maycontrol the battery backup unit 300 so as to test validity of the firstbattery module 310-1 during a first period and to test validity of asecond battery module 310-2 during a second period, wherein the firstperiod and the second period are not overlapped with each other. Thevalidity test periods on other battery modules 310-3˜310-n may bearranged similarly. Thus, during any test period, the rack server system200 may be powered by battery modules not under validity test, and therisk of data loss of the rack server system may thus be reduced.

In some other embodiments, the control unit 230 may control the batterybackup unit 300 to test validity of a part of the battery modules (suchas two or more battery modules) during a first period and test validityof another part of the battery modules (such as another two or morebattery modules) during a second period. Thus, during any test period,the rack server system 200 may be powered by battery modules not undervalidity test, and risk of data loss of the rack server system can thusbe reduced.

For the battery backup unit 300, each of the battery modules 310-1-310-nincludes similar elements. Let the battery module 310-1 be taken forexample. The battery module 310-1 includes a power supply port 311-1, aDC-to-DC converter 312-1, and a battery 313-1. The power supply port311-1 is coupled to the power input port 210 of the rack server system200. The DC-to-DC converter 312-1 is connected between the battery 313-1and the power supply port 311-1 for converting a voltage of the battery313-1 into a voltage for the rack server system 200. The battery 313-1is such as a secondary battery or other type. In some implementationexamples, the battery 313-1 is such as a lithium battery. In some otherimplementation examples, the battery 313-1 is such as a reusablebattery, a rechargeable battery or a replaceable battery.

The arrangement of a number of battery modules increases the powersupply stability of the battery backup unit 300. In other words, if onebattery module fails, other battery modules of the battery backup unit300 still provides power to the rack server system 200. Thus, stabilityof the rack server system 200 is kept so as to reduce risk of data lossof the rack server system.

Moreover, for the battery backup unit 300, via the validity test, thecontrol unit 230 knows whether the battery backup unit 300 fails due toaging or other factors, so as to assure validity of the battery backupunit 300. In an implementation example, the validity test on the batterybackup unit 300 is such as discharge test. During the discharge test,the battery backup unit 300 increases its output voltage so as toprovide energy to the rack server system 200. In other implementationexample, if the battery backup unit 300 uses lithium battery, then thevalidity test is a learning curve test which records the relationshipbetween usage time and voltage. However, the disclosure is not limitedto such exemplification, and the validity test on the battery backupunit 300 is based on the types of the battery modules or on userrequest.

Referring to FIG. 3A and FIG. 3B, timing diagrams of an example of thecommunication between the rack server system and the battery backup unitof FIG. 2 are shown. The disclosure is further elaborated below inconjunction with FIG. 2 and FIGS. 3A and 3B.

At step S310, the rack server system 200 establishes a communicationlink for communicating with the battery backup unit 300.Correspondingly, in step S410, the battery backup unit 300 communicateswith the rack server system 200.

In step S312, the rack server system 200 reads previous data to obtainresult(s) of previous validity test(s) and execution time(s) on thebattery backup unit 300. Correspondingly, in step S412, the batterybackup unit 300 provides previous test data to the rack server system200. Test data is stored in a memory of the battery backup unit 300,such as a non-volatile memory. Data read by the rack server system 200are information such as the execution time and the result of a previousvalidity test on the battery modules 310-1˜310-n, or other informationsuch as lifespan, manufacturer, manufacture date, and electricalcharacteristics.

In step S314, the rack server system 200 plans or arranges the executiontimes and test sequence of validity tests on the battery modules310-1˜310-n. The rack server system 200 such as plans or arranges theexecution times and sequence of validity tests on the battery modules310-1˜310-n according to the read data. For example, considering systemstability, the execution times of validity tests on the battery modules310-1˜310-n are neither concurrent nor overlapped with each other. Theexecution sequences of validity test on the battery modules 310-1˜310-nare such as determined according to previous execution times. Forexample, the earlier the previous test time on a battery module, thehigher sequence priority of the validity test on the battery module. Theexecution time of validity tests on the battery modules 310-1˜310-n aredetermined according to previous execution results of the batterymodules 310-1˜310-n. For example, the battery module(s) which was/werefailed in the previous validity test may be not tested so as to reducethe total test time.

In step S316, the rack server system 200 sends a command to notify thebattery backup unit 300 for a validity test. Correspondingly, in stepS416, the battery backup unit 300 receives the command to begin validitytest. For example, the battery backup unit 300 increases the outputvoltage to release energy.

In step S318, the rack server system 200 receives a return dataindicating the test result. Correspondingly, in step S418, the batterybackup unit 300 determines the state of the battery module(s) undertest. If the test result indicates “pass”, then the method proceeds tostep S422, the battery backup unit 300 charges the battery module(s)passed in the test, and after charging finishes, the battery backup unit300 transmits the return data and the method proceeds to step S318. Ifthe test result indicates “fail”, then the method proceeds to step S420,the battery backup unit 300 controls an indicator such as a lightemitting diode (LED) to generate an indication signal such as a lightsignal indicating failure of the battery module(s) under test. Someembodiments may further include other steps for generating the returndata indicating the test result or steps for storing the test result toa memory (not shown) of the battery backup unit 300.

In step S320, the rack server system 200 determines the result ofvalidity test on the battery module(s) according to the return data. Ifthe test result indicates “fail”, then the method proceeds to step S322.If the test result indicates “pass”, then the method proceeds to stepS324.

In step S322, the rack server system 200 generates the indicationsignal, such as a light signal, an audio signal, or a signal fordisplaying a message on a screen, to notify or remind the user toreplace the battery module. Then, the method proceeds to step S324.

In step S324, the rack server system 200 stores the results of validitytest. Via the communication interface 220, the test result istransmitted to the control unit 230 and may be further stored in amemory (not shown) of the control unit 230 or other memory not shown.

In step S326, the rack server system 200 determines a default loadingaccording to the results of validity tests on the battery modules310-1˜310-n. The default loading determines efficiency of the rackserver system 200 when abnormality occurs to the main power supplied tothe rack server system 200. The default loading such as determines theloading of the rack server system when abnormality occurs to the mainpower.

In some embodiments, the default loading determines the number of normaloperating servers of the rack server system when abnormality occurs tothe main power. For example, under full-loading, the rack server system200 may activate all servers so as to operate at high efficiency and athigh power consumption. Under half-loading, the rack server system 200activates half of the servers and shut down another half of the serverssafely, and both efficiency and power consumption are reduced.

In some embodiments, the default loading determines operation frequencyof a processor of each server of the rack server system when abnormalityoccurs to the main power. For example, under full-loading, the processorof each server of the rack server system 200 operates at highestoperation frequency, high efficiency but high power consumption. Underhalf-loading, the operation frequency of the processor of each server ofthe rack server system 200 is half, and efficiency and power consumptionare reduced.

The above default loading for determining the number of the activeservers and/or for determining the operation frequency of the processorof the server is for exemplification purpose not for limiting thedisclosure. The default loading may also be other parameters relating tothe efficiency, loading, or power consumption of the rack server systemwhen abnormality occurs to the main power.

In some embodiments, when a battery module is failed in the validitytest, the rack server system 200 may reduce the default loading. Thedefault loading is such as reduced according to the number of the failedbattery modules. Suppose 10 battery modules are used, and the initialdefault loading is full-loading. When one battery module fails, thedefault loading may be reduced by 1 tenth as 9-tenth loading. When ahalf of the battery modules fails, the default loading may be reduced by5 tenths as half-loading. Thus, when abnormality occurs to the mainpower of the rack server system 200, the rack server system 200 avoidsoperating at high efficiency and/or high power consumption. Thus, thestability of the rack server system is kept so as to reduce the risk ofdata loss of the rack server system.

Referring to FIG. 4, a block diagram of another example of a rack serversystem and a battery backup unit according to one embodiment of thedisclosure is shown.

In the present example, the rack server system 400 includes a powerinput port 410, a system communication interface 420, and a systemcontrol unit 430. The operations of the rack server system 400 aresimilar to that of the rack server system 200 of FIG. 2, and thesimilarities are not repeated here.

The battery backup unit 500 includes a number of battery modules510-1˜510-n connected in parallel, and further includes a batterycommunication interface 520 and a battery control unit 530. The batterycontrol unit 530 and the rack server system 400 communicate with eachother and may implement the above control method.

The battery control unit 530 may execute a part of operations of thesystem control unit 430. For example, the battery control unit 530receives a notification from the system control unit 430 and controlsthe battery modules 510-1˜510-n to perform validity test intime-sharing. In another example as indicated in step S314, the batterycontrol unit 530 may plan and arrange the execution time and sequence ofvalidity test.

No matter the rack server system controls the battery backup unit toperform validity test or the rack server system notifies the controlunit of the battery backup unit to perform validity test, those arepossible embodiments of the disclosure as long as battery modules of thebattery backup unit are tested in time-sharing.

According to the rack server system and the control method thereof ofthe present embodiment of the disclosure, the battery backup unitincludes a number of battery modules connected with each other inparallel and the battery modules are controlled by the rack serversystem via the communication interface to be tested such as a dischargetest in a time-sharing manner, so as to reduce the risk of data loss ofthe rack server system.

In some embodiments, with the configuration of the battery backup unit(which is modularized) and the communication interface, the rack serversystem notifies the battery modules to be under test (i.e. systemcontrol). The advantage of system control is that all loading conditionsare taken into consideration to avoid interrupt of power supply duringtest or due to failure of the battery module. In cooperation with thebattery backup unit which is modularized, the system controls thebattery modules under validity test at different periods (i.e. intime-sharing), so as to keep system stability.

In some other embodiments, the power consumption of the rack serversystem when abnormality occurs to the main power may be determinedaccording to the results of validity tests on the battery modules, so asto avoid the rack server system operating at high efficiency and highpower consumption. Thus, the risk of data loss of the rack server systemmay be further reduced.

It will be appreciated by those skilled in the art that changes could bemade to the disclosed embodiments described above without departing fromthe broad inventive concept thereof. It is understood, therefore, thatthe disclosed embodiments are not limited to the particular examplesdisclosed, but is intended to cover modifications within the spirit andscope of the disclosed embodiments as defined by the claims that follow.

What is claimed is:
 1. A control method applicable to a rack serversystem, comprising: establishing a communication link between the rackserver system and a battery backup unit, wherein the battery backup unitis connected to a power input port of the rack server system, andcomprises a plurality of battery modules connected with each other inparallel; controlling the battery backup unit by the rack server systemto perform a validity test on a first battery module of the batterymodules during a first period, wherein the validity test furthercomprises increasing the output voltage of the battery backup unitsupplied to the rack server system while the rack server system issupplied with a main power to the rack server system; controlling thebattery backup unit by the rack server system to perform the validitytest on a second battery module of the battery modules during a secondperiod, wherein the first period and the second period are notoverlapped with each other; and determining a default loading by therack server system based at least upon the results of the validity testson the first battery module and the second battery module, wherein thedefault loading is adjusted based at least upon a number of batterymodules that failed the validity test.
 2. The control method accordingto claim 1, further comprising: receiving a return data from the batterybackup unit to the rack server system; and determining a result of thevalidity test on the first battery module by the rack server systemaccording to the return data.
 3. The control method according to claim1, wherein the validity test on the first battery module or the secondbattery module includes a discharge test.
 4. The control methodaccording to claim 1, further comprising: determining a default loadingby the rack server system according to results of validity test on thebattery modules, wherein the default loading determines efficiency ofthe rack server system when abnormality occurs to a main power suppliedto the rack server system.
 5. The control method according to claim 4,wherein when the validity test on one of the battery modules showsfailed, the rack server system reduces the default loading.
 6. Thecontrol method according to claim 5, wherein the rack server systemreduces the default loading according to a number of failed batterymodules.
 7. The control method according to claim 4, wherein the defaultloading determines a loading of the rack server system when abnormalityoccurs to the main power.
 8. The control method of claim 1, wherein thevalidity test further comprises: measuring the usage time and voltageoutput of the first battery module; recording the usage time and voltageoutput of the first battery module; comparing the usage time and voltageoutput of the first battery module to previous usage time and voltageoutput of the first battery module to determine performance data of thebattery module; and communicating the performance data to the rackserver system.
 9. The control method according to claim 1, wherein thevalidity test on the first battery module or the second battery moduleis performed on a time-sharing basis.
 10. A rack server system,comprising: a power input port connected to a battery backup unit,wherein the battery backup unit comprises a plurality of battery modulesconnected with each other in parallel; a communication interfaceestablishing a communication link for communicating with the batterybackup unit; a control unit connected to the communication interface forcontrolling the battery backup unit to perform a validity test on afirst battery module of the battery modules during a first period byincreasing the output voltage of the battery backup unit supplied to therack server system and controlling the battery backup unit to perform avalidity test on a second battery module of the battery backup unitduring a second period by increasing the output voltage of the batterybackup unit supplied to the rack server system, wherein the first periodand the second period are not overlapped with each other; and whereinthe rack server system further determines a default loading based atleast upon results of the validity tests on the first battery module andthe second battery module; and wherein the default loading is adjustedbased at least upon a number of battery modules that failed the validitytest.
 11. The rack server system according to claim 10, wherein eachbattery module comprises: a power supply port connected to the powerinput port of the rack server system; a battery; and a DC-to-DCconverter connected between the battery and the power supply port. 12.The rack server system according to claim 11, wherein the battery is asecondary battery.
 13. The rack server system according to claim 10,further comprising: a communication bus connecting the communicationinterface to the battery backup unit.
 14. The rack server systemaccording to claim 10, wherein the rack server system further receives areturn data from the battery backup unit, and determines a result of thevalidity test on the first battery module according to the return data.15. The rack server system according to claim 10, wherein the validitytest on the first battery module or the second battery module includes adischarge test.
 16. The rack server system according to claim 10,wherein the rack server system further determines a default loadingaccording to results of validity tests on the battery modules, and thedefault loading determines efficiency of the rack server system whenabnormality occurs to a main power supplied to the rack server system.17. The rack server system according to claim 16, wherein the firstbattery module is failed in the validity test, the rack server systemreduces the default loading.
 18. The rack server system according toclaim 17, wherein the rack server system includes the default loadingaccording to a number of failed battery modules.
 19. The rack serversystem according to claim 16, wherein the default loading determines aloading of the rack server when abnormality occurs to the main power.20. The rack server system according to claim 10, wherein the batterybackup unit further comprises: another communication interface connectedto the battery modules; and another control unit connected to theanother communication interface and controlled by the rack system forcontrolling the battery modules to perform the validity test.
 21. Therack server system according to claim 16, wherein the default loadingdetermines operation frequency of a processor of each server of the racksystem server when abnormality occurs to main power.
 22. The rack serversystem of claim 10, wherein the validity test further determines theusage time and voltage output of the first battery module, records theusage time and voltage output of the first battery module, compares andrecords the usage time and voltage output of the first battery module todetermine performance data, and communicates the performance data to therack server system.